calibre Debug log
calibre 2.99.8* [64bit]  embedded-python: True is64bit: True
Windows-10-10.0.14393-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.14393')
Python 2.7.12+
Windows: ('10', '10.0.14393', 'SP0', u'Multiprocessor Free')
Successfully initialized third party plugins: DeDRM (6, 5, 3) && Job Spy (1, 0, 55) && EpubMerge (2, 1, 0) && Diaps Editing Toolbag (0, 3, 4) && Find Duplicates (1, 6, 2) && food network Recipe Reader (1, 0, 2) && Manage Sony x50 Reader Book List (1, 2, 11) && Annotations (1, 4, 11) && Quality Check (1, 9, 11) && Library Codes (1, 0, 30) && Wiki Reader (2, 1, 0) && KoboTouchExtended (2, 8, 2) && KindleUnpack - The Plugin (0, 81, 4) && ScrambleEbook (0, 0, 5) && Favourites Menu (1, 0, 4) && Media File Importer (1, 0, 19) && BOL_DE (0, 7, 5) && Open With (1, 5, 10) && Count Pages (1, 7, 0) && Goodreads (1, 1, 12) && Extract ISBN (1, 4, 4) && EpubSplit (2, 2, 0) && Generate Cover (1, 5, 21) && Goodreads Sync (1, 10, 1) && Search The Internet (1, 7, 6) && Import List (1, 1, 5) && Modify ePub (1, 3, 13)
calibre 2.99.8* [64bit]  embedded-python: True is64bit: True
Windows-10-10.0.14393-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.14393')
Python 2.7.12+
Windows: ('10', '10.0.14393', 'SP0', u'Multiprocessor Free')
Successfully initialized third party plugins: DeDRM (6, 5, 3) && Job Spy (1, 0, 55) && EpubMerge (2, 1, 0) && Diaps Editing Toolbag (0, 3, 4) && Find Duplicates (1, 6, 2) && food network Recipe Reader (1, 0, 2) && Manage Sony x50 Reader Book List (1, 2, 11) && Annotations (1, 4, 11) && Quality Check (1, 9, 11) && Library Codes (1, 0, 30) && Wiki Reader (2, 1, 0) && KoboTouchExtended (2, 8, 2) && KindleUnpack - The Plugin (0, 81, 4) && ScrambleEbook (0, 0, 5) && Favourites Menu (1, 0, 4) && Media File Importer (1, 0, 19) && BOL_DE (0, 7, 5) && Open With (1, 5, 10) && Count Pages (1, 7, 0) && Goodreads (1, 1, 12) && Extract ISBN (1, 4, 4) && EpubSplit (2, 2, 0) && Generate Cover (1, 5, 21) && Goodreads Sync (1, 10, 1) && Search The Internet (1, 7, 6) && Import List (1, 1, 5) && Modify ePub (1, 3, 13)
Turning on automatic hidpi scaling
devicePixelRatio: 1.0
logicalDpi: 96.0 x 96.0
physicalDpi: 90.0253164557 x 90.1013513514
Using calibre Qt style: True
Starting up...
Calibre, and hence Job Spy, was gracefully shut down last time?  True
Last time daemon started:  Thu Feb 16 09:34:56 2017
Last time daemon failed:  never
Total daemon starts inception_to_date:  1
Total daemon failures inception-to-date:  0
Job Spy has finished initialization...
EpubMerge: DEBUG: 2017-05-27 20:53:27,513: calibre_plugins.epubmerge.epubmerge_plugin(152): macmenuhack file_path:C:\Users\Armin\AppData\Roaming\calibre\plugins\fanficfare_macmenuhack.txt
DEBUG:    0.0 HttpHelper::__init__: proxy=None
C:\Program Files\Calibre2\app\pylib.zip\dateutil\parser.py:601: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 1487, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #in_virtual_library
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 340, in evaluate
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 133, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 370, in evaluate
RuntimeError: maximum recursion depth exceeded
Error evaluating column named: #readingtime
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #isbn
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #lc_authority_name_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #oclc_classify_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 596, in _vformat
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 290, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 264, in _eval_program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 107, in program
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 114, in statement
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 170, in expr
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 132, in eval_
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter_functions.py", line 828, in evaluate
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #pathfilename
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #viaf_author_id_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Traceback (most recent call last):
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 375, in safe_format
  File "c:\Users\Armin\git\calibre\src\calibre\utils\formatter.py", line 342, in evaluate
  File "string.py", line 563, in vformat
  File "string.py", line 585, in _vformat
  File "string.py", line 646, in get_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\formatter.py", line 40, in get_value
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 618, in format_field
  File "c:\Users\Armin\git\calibre\src\calibre\ebooks\metadata\book\base.py", line 641, in format_field_extended
  File "c:\Users\Armin\git\calibre\src\calibre\db\lazy.py", line 380, in custom_field_keys
  File "c:\Users\Armin\git\calibre\src\calibre\library\field_metadata.py", line 472, in custom_field_keys
  File "collections.py", line 119, in keys
RuntimeError: maximum recursion depth exceeded while calling a Python object
Error evaluating column named: #loc_lccn_url
Started up in 37.64 seconds with 3526 books
MFI self.tmp_directory never used; returning True for shutdown.
